Drill outs or LH Drill Bits?

[mikey9]

Snapped Exhaust stud - getting it out (I know there are loads of threads - I have read them all!)

Anyone used these..and would you recommend - otherwise where to get LH drill bits from?

http://www.frost.co.uk/item_Detail.asp? ... ill%20outs

edited by rob to make link work....

[Mr Bean]

Snapped Exhaust stud - getting it out (I know there are loads of threads - I have read them all!)Anyone used these..and would you recommend - otherwise where to get LH drill bits from?http://www.frost.co.uk/item_Detail.asp? ... ill%20outsedited by rob to make link work....

No. But the same effect could be got using a proper drill first then followed by a conventional screw extractor. IMHO clever attempts to combine more than one device must have a drawback somewhere. I can see where they are coming from but they do nothing to get round the two main problems with LH drive screw extractors:1/ determining the middle of the stud when the bare metal displayed to you is the shape of a snail due to the helical nature of the thread.2/ If you use a size which leaves plenty of meat it will be too weak. But if you use a more suitable size the extractors tapered thread will simply expand the stud and  jam it even harder in the casting.In addition to this the drill is a spade type which would not be my first choice in old, high tensile and therefore cantakerous metal. I have not found a surefire method of removing busted studs and assess each one depending on its circumstances. In some scases it is possible to drill a row of holes across it and use a screwdiver. In others a sharp centre punch can be used to rotate it anticlockwise If enough is exposed I will weld a nut on the top which also applies heat. In the death I will just carry on enlarging the drill size untill I can pick the thread out with a dental probe. Whatever you do heat (and I mean heat) together with a squirt of oil will alway help or at least kid you on you are getting somewhere.Hope this helps

[syncrosimon]

Have to agree with Ken....ooops sorry thats Smiffy.

Those extractors look like they are meant for big stuff.

Welding has got to be the best route. If the nut or stud simply wont budge, dont snap it off, but cut it off, this will leave the old stud at least flush, which will allow welding of a nut. The first time you do this is like a eureka moment, you have just spent hours fidling around, cursing and skinning your knockles, then 3 seconds welding, and the stud comes out oh so easily.

In my honest opinion wd-40 etc only works when you get something moving. If there is enough gap to allow the oil in, then it's a loose fit. A rusted stud is not gonna let in any oil. Get it moving though, and you want to spend some time going in and out, with loadsa wd-40 until it comes out nice and easy. Makes fitting the new one so much easier.

When it comes to new exhaust time for me I will take the engine out, do all the other little things aswell, then if it needs helicoiling at least I can take it somewhere to be done.

[CovKid]

Not sure how succesful this would be in removing exhaust studs generally but over many years hard experience its often better to do something up an eight of a turn before trying to undo it. Shifted many nuts, bolts and studs that way - particularly brake bleed valves!

[Steve T]

But is there an alternative? Why bust your balls, if you can weld a nut and is strong enough to eventualy get the busted bolt out, its strong enough to hold the exhaust in place. Why not weld a threaded rod and bolt the exhaust to that with suitable nut. I know its not as it should be but with carfull countersink on the sheared bolt should give enough to get a weld joint round to hold the threaded rod in place, if your handy with a welder that is. Is there any one that has tried this or would concider useing or is it a complete no no, and reasons why

Steve

[mikey9]

Cheers for the replys.

This has come about as a result of the engine replacement thread

https://club8090.co.uk/forum/viewtopic.p ... highlight=

The last bit - now the engine is working well - is to sort a small blow from the exhaust (I assumed just wasn't nipped up on one joint) however I found NO bolt or nut and just a blob of weld on one of the front left manifold stud/bolts.
Rang the gge who did the install who have told me that they had indeed had one stud snap off (flush I think) removing the old exhaust off the replacement engine - and had built up weld to use to attach to.

Credit to them - they have accepted it is their issue so is going back in week monday for retrospective action.

My fear is - as it is the innacessible one - they REALLY have to drop the engine again to get at it properly to drill out - althought they were talking about taking the head off....noooooooooooo I will tell them thought to that suggestion....

Blooming frustrating given we appear to have sorted everything else and it is running well on Gas and petrol now.......

[Syncro G]

Wouldn't bother with an extractor bolt unless its something soft like brass thats got mashed and it'll still be easy to turn.

My Dad has herd of these extractor things and thought it would be a great idea to remove a broken bolt in an engine block - the bolt had snapped as it was rusted in really hard. On screwing one of these things in (obveously much thinner than the bolt) he found it still didn't shift to the point the very hard (but much thinner than the original bolt) extractor snapped - now rather than a soft drillable bolt that could have been overbored and retapped or just bored and helicoiled we have a very hard thread tap in the way! The genral consensus on removing it goes along the lines of "you've got a problem there!" Engine blocks being as they are, not the easyest things to try and put in a machine. He's now found out what Helicoiling is, sadly I'd have told him that first off if he'd told me what he was doing before trying the extractor - lives and learns though, luckally the waterpump doesn't seem to mind lacking a bolt (not a VW engine).

As for duck oils like WD40 in something seazed, they do creap into seemingly nonexistant gaps so do help ease things. Do yourself a favour though and ditch the WD40 in favour of "plusgas" Much better! WD40 is famous and avalable but its far from the best, kinda like Lipton tea (aparently, don't do tea).

[lloyd]

Can't agree more Glen. WD40 IS NOT PENETRATING OIL!! WD stands for Water Displacement. WD40 IS NOT A LUBRICANT!! It evaporates away in a week or so. Not saying it doesn't have it's uses.. I use it alot .. for all kinds of things other then penetrating and lubricating. Like on stuck hinges... pentatrant first to get it moving, then WD and keep working it to clean rust/crud out, then good oil to lubricate it.

Left hand drill bits are pants. Have a full set of them... It's amazing how many bolts and screws will come out while drilling them!... expecially if using a good pentrating oil at same time. If they don't come out, I use dental picks and a custom made chisel to cut remaining threads loose as needed. I never use ez-outs for same reasons stated above. They expand bolt locking it even harder in hole, and if they break, well, lots of crying doesn't help. Cursing sometimes helps release frustration, but bolt is buggered.

Good penetrating oil (use gas plus) days before doing work if possible, try loosening, if no-go, heat with torch and try loosening/tightening again, still no-go more penetrating oil, heat, time to work etc. There are a couple of new penetrating oils that use freezing spray to freeze bolt (shrink it) so penetrant can get in easier. Haven't tried one yet, but supposed to be good.